Viscosity and conductivity properties of Li-salts (lithium tetrafluoroborate (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bis-(trifluoromethylsulfone)-imide (LiTFSI)) dissolved in γ-butyrolactone (BL) have been investigated. The B- and D-coefficients of the Jones-Dole (JD) equation for the relative viscosity of concentrated electrolyte solutions (concentration: C=0.1-1.5M): η r =1+AC 1 / 2 +BC+DC 2 , have been determined as a function of the temperature. The B-coefficient is linked to the hydrodynamic volume of the solute and remains constant within the temperature range investigated (25-55 o C). The D-coefficient, which originates mainly from long-range coulombic ion-ion interactions, is a reciprocal function of the temperature. The variations of the molar conductivity (Λ) with C follow the cube root law Λ=Λ 0 ' -S'C 1 / 3 issued from quasi-lattice theory of electrolyte solutions. From the Walden product W=Λη which does not vary with C and the JD equation, the bell shape of the conductivity-concentration relationship is explained and it is shown that the concentration in salt at the maximum of conductivity is linked to the D-coefficient. Raman spectroscopy has been used as an additional tool to investigate ion pairing in BL. Ions pairs have been evidenced for LiClO 4 solutions in BL but not for LiPF 6 . As little variations occur for the ions pairs dissociation coefficient when the salt concentration is increased, the cube root law remains valid, at least in the concentration range investigated.